{
  "model": {
    "type": "select",
    "property": "component",
    "component": "custom_name",
    "fallback": {
      "type": "model",
      "model": "minecraft:item/emerald"
  },
  "cases": [
    {
      "when": "Ruby",
      "model": {
        "type": "model",
        "model": "default_beta:item/ruby"
      }
    }
  ]
}
}